This application is related to and claims priority from Japanese Patent Applications No. Hei. 11-59254 filed on Mar. 5, 1999, No. Hei. 11-194793 filed on Jul. 8, 1999 and No. Hei. 11-324570 filed on Nov. 15, 1999, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a receiver-integrated condenser in which a condensing portion for cooling and condensing refrigerant, a receiving unit for separating gas refrigerant and liquid refrigerant from the condensing portion, and a super-cooling portion for super-cooling liquid refrigerant from the receiving unit are integrally formed. The receiver-integrated condenser is suitably used for a vehicle air conditioner.
2. Description of Related Art
JP-A-5-141812 describes a receiver-integrated condenser in which a condensing unit for condensing refrigerant and a receiving unit for separating refrigerant from the condensing unit into gas refrigerant and liquid refrigerant are integrally formed. In the conventional receiver-integrated condenser, two supplementary passages extending in a tank longitudinal direction are provided between a header tank of the condensing unit and the receiving unit. Therefore, the header tank of the condensing unit and the receiving unit communicate with each other through the supplementary passages, and the supplementary passages are used as a heat-insulating space between the header tank and the receiving unit. However, because a super-cooling portion for super-cooling liquid refrigerant separated in the receiver is not provided, a super-cooling degree of high-pressure side liquid refrigerant in a refrigerant cycle is not improved.
On the other hand, in a receiver-integrated condenser described in U.S. Pat. No. 5,546,761, a super-cooling portion for super-cooling liquid refrigerant separated in a receiving unit is disposed at a lower position of a core portion of a condensing unit. That is, for stably introducing liquid refrigerant into the super-cooling portion from the receiving unit, liquid refrigerant is introduced from a bottom side of the receiving unit, and the super-cooling portion is set at a lowest position of the core portion. However, during an engine idling such as in a case where a vehicle waits for the traffic lights to change, because an air flow due to a travelling dynamical force is not generated, a high-temperature air having passed through the receiver-integrated condenser and a radiator may be introduced into again an upstream air side of the receiver-integrated condenser through a lower side portion of the receiver-integrated condenser by the operation of a cooling fan. Thus, the lower side of the condensing unit is restricted from cooling, and the super-cooling performance of liquid refrigerant in the super-cooling portion is greatly reduced.
In view of the foregoing problems, it is an object of the present invention to provide a receiver-integrated condenser having a super-cooling member, which prevents cooling performance of liquid refrigerant in the super-cooling member from being decreased due to high-temperature air passing therethrough.
It is an another object of the present invention to provide a receiver-integrated condenser in which a refrigerant passage structure is made simple and an arrangement position of a super-cooling member is readily set.
It is a further another object of the present invention to provide a receiver-integrated condenser for a refrigerant cycle, in which a refrigerant sealing amount of the refrigerant cycle is readily checked.
It is a further another object of the present invention to provide a hole forming method for a receiver-integrated condenser.
According to the present invention, a receiver-integrated condenser for a refrigerant cycle includes a condensing member for cooling and condensing super-heating gas refrigerant from a compressor of the refrigerant cycle, a receiving unit for separating refrigerant from the condensing member into gas refrigerant and liquid refrigerant and for storing liquid refrigerant therein, and a super-cooling member for super-cooling liquid refrigerant from the receiving unit. The receiving unit is integrated with the condensing member, and the super-cooling member is integrated with the condensing member. Further, the condensing member includes a first condensing portion at an upper side from the super-cooling member, and a second condensing portion at a lower side from the super-cooling portion. In the receiver-integrated condenser, the super-cooling member is disposed between the first and second condensing portions in a vertical direction. Thus, in an engine idling such as in a case where a vehicle waits for the traffic lights to change, high-temperature air having passed through the receiver-integrated condenser and a radiator is not introduced again toward the arrangement position of the super-cooling member. As a result, even in the engine-idling, the cooling performance of the super-cooling member is improved. Further, because the super-cooling member is disposed between the first and second condensing portions in the vertical direction, the super-cooling member is positioned around a high-air distribution area of a cooling fan, and cooling effect of refrigerant in the super-cooling member is further improved.
Preferably, the receiver-integrated condenser includes a core portion having a plurality of tubes through which refrigerant flows in a horizontal direction, a first header tank extending in a vertical direction perpendicular to the horizontal direction and being connected to each one side end of the tubes to communicate with the tubes, a second header tank extending in the vertical direction and being connected to each the other side end of the tubes to communicate with the tubes, and a wall member for defining first and second communication passages. In the receiver-integrated condenser, the core portion is disposed to define the condensing member and the super-cooling member for super-cooling liquid refrigerant, and the receiving unit is integrated with the second header tank. Refrigerant from the condensing member is introduced toward the receiving unit through the first communication passage, liquid refrigerant separated in the receiving unit is introduced toward the super-cooling member through the second communication passage, and the first and second communication passages are arranged in parallel to extend in the vertical direction along the second header tank and the receiving unit between the second header tank and the receiving unit.
In the receiver-integrated condenser, at least two parts of the second header tank, the receiving unit and the wall member for defining the first and second communication passages are an integrally molded member. Therefore, a refrigerant passage structure of the receiver-integrated condenser is made simple using the first and second communication passages, and the arrangement position of the super-cooling member is readily changed in the vertical direction.
Preferably, the receiver-integrated condenser further includes a cover member for closing at least an upper side opening of the second communication passage, and a sight glass for checking a gas-liquid state of refrigerant in the second refrigerant passage. The sight glass is disposed in the cover member. Because liquid refrigerant from the receiving unit flows through the second communication passage, a gas-liquid state of refrigerant at an outlet of the receiving unit is readily determined through the sight glass. Therefore, refrigerant sealing operation is accurately performed in accordance with the gas-liquid state of refrigerant at the outlet of the receiving unit. Further, because the sight glass is provided in the cover member at the upper end opening of the second communication passage, the gas-liquid state of refrigerant is readily checked from the sight glass without any additional operation.
According to an another aspect of the present invention, a first communication pipe is disposed outside a second header tank and a receiving unit so that liquid refrigerant within a receiving unit flows toward a super-cooling member through the first communication pipe. Therefore, using the first communication pipe, the arrangement position of the super-cooling member is readily changed. Further, a connection structure between the second header tank and the receiving unit is made simple because the first communication pipe is disposed outside the second header tank and the receiving unit.
Further, the second header tank and the receiving unit are disposed to have a communication hole therebetween through which refrigerant having passed through the second header tank from the condensing member flows toward the receiving unit. Further, a second communication pipe is disposed outside the second header tank and the receiving unit in such a manner that refrigerant passing through the condensing member flows through a refrigerant passage defined by the second communication pipe. Therefore, the refrigerant passage structure is further made simple.
According to a further another aspect of the present invention, a hole forming method for forming a communication hole in a partition member for partitioning an interior portion of a pipe-like outer wall of a heat exchanger into plural spaces includes: inserting a punch member in a space between the partition member and the outer wall at a predetermined position; attaching and contacting a pressing jig onto the punch member through a hole portion provided in the outer wall; and adding a press force to the punch member by the pressing jig so that the partition member is punched by the punch member to form the communication hole. Thus, pressing force is vertically applied from a directly upper side of the punch member to the punch member by using the pressing jig attached through the hole portion of the outer wall. As a result, punch load is accurately applied to the partition member, and the communication hole is accurately punched. Accordingly, when the hole forming method is applied to a receiver-integrated condenser, a communication hole is readily formed in a partition member.